A well-known use for thermoelectric devices is for the extraction of electric power from waste heat. For example, U.S. Pat. No. 6,527,548 discloses a self powered space heater for a truck in which heat energy for the heater is used to power electric components of the heater plus charge a battery. In U.S. Pat. No. 6,053,163 heat from a stovepipe is used to generate electricity. U.S. Pat. No. 6,019,098 discloses a self-powered furnace. Various types of thermoelectric modules are available. A very reliable thermoelectric module with a gap-less egg-crate design is described in U.S. Pat. Nos. 5,875,098 and 5,856,210. U.S. Pat. No. 6,207,887 discloses a miniature milli-watt thermoelectric module useful in space applications (and special applications on earth) in combination with radioactive heat source.
A typical thermoelectric module is Hi-Z Model HZ-2, commercially available from Hi-Z Corporation with offices in San Diego, Calif. It is a square module with 2.9 cm sides and is 0.5 cm thick. It produces about 2 watts at 4 volts when sandwiched between hot and cold surfaces with a temperature difference of about 200 degrees centigrade. This unit sells for less than $50.
Quantum well very thin layer thermoelectric modules are known. Some are described in U.S. Pat. Nos. 6,096,965, 6,096,964, 5,436,467 and 5,550,387. U.S. Pat. No. 6,624,349 describes an electric generator using a thermoelectric module to generate electric power from the heat of fusion produced by the freezing of a phase change material. All of the above referenced patents are assigned to Applicant's employer and they are all incorporated herein by reference.
Tracking and surveillance devices are available for tracking vehicles. Devices are available that can be attached to an motor vehicle that will transmit radio signals indicating the latitude and longitude of the motor vehicle to a monitoring stations. Trucking systems can use these systems to keep track of its vehicles as they traverse the United States. Police can attach these devices to motor vehicles of evil people to keep track of them. These devices are typically powered by batteries so that their useful life is limited. A typical tracking device is a Model ST-18 PTT available from Telonics, Inc with offices in Mesa Ariz. The unit operates at 4 volts and requires about ½ watt to transmit via the Argos tracking system. Argos is a satellite-based system in operation since the late 1970's and is utilized world wide to track just about anything from ships, to trucks to birds.
The phrase “magnetic materials” is a phrase generally applied to materials exhibiting ferromagnetism. In this patent application the phrase will be used to describe materials such as iron, nickel or cobalt and alloys of these material and products made from these materials and their alloys (such as tail pipes and mufflers) to which magnets are strongly attracted.
Most of the waste heat in industry, motor vehicles, commercial and residential situations is transported away in pipes. Only a very small portion of the energy in this waste heat is recovered.
What is needed is a product that can produce small amounts of electric power from a hot or cold surface and can be attached to the surface quickly and easily especially for the recovery of energy from waste heat.